JP2019113179A - Drive arrangement - Google Patents

Abstract

To provide a drive arrangement for adjusting an aerodynamic flap on a vehicle, which includes an electric motor, a gear mechanism having multiple gear stages, an output shaft, and at least two housing halves.SOLUTION: In a drive arrangement, a gear mechanism includes multiple spur gears (7, 11, 14, 15) and at least one self-locking gear stage (S), where the self-locking gear stage (S) forms neither the first gear stage nor the last gear stage of the gear mechanism.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drive arrangement for adjusting an aerodynamic flap on a vehicle.

  With the aim of improving the efficiency of motor vehicles, there is an increasing effort to actively change the aerodynamics of the vehicle. For this purpose, each part of the outer surface of the vehicle (flap, spoiler, diffuser, etc.) is electrically adjusted according to the speed of movement in order to advantageously influence the air flow around the vehicle.

  The exposed position of the drive required for this adjustment requires a watertight housing. Therefore, housings that are welded and closed are frequently used.

  Preferably, self-locking gear mechanisms are used in order to be able to hold the adjusted flaps as efficiently as possible against the wind. In this case, the drive may have a safety coupling, which disconnects the output drive upon overloading to protect the flaps mounted on the output drive from damage.

  A drive of this kind is described in WO 2014205217.

  In order to achieve the required high power moments in this type of drive, multi-stage gear mechanisms are usually used with at least one self-locking stage. The usual design is a two-stage worm gear mechanism. The advantage of this design is the small number of components, but the major disadvantage is that the gear efficiency is poor and the electric motor is correspondingly large.

  It is already known that the output shaft is preferably separable from the remaining gear mechanism by means of a safety coupling. However, a disadvantage of this known device is that the coupling requires considerable installation space when a large release moment is required.

  The object of the present invention is to specify a drive for the adjustment of the aerodynamic flaps on a motor vehicle which avoids the above-mentioned drawbacks, in particular of high efficiency with less installation space.

  The object is a drive for adjusting an aerodynamic flap on a vehicle comprising an electric motor, a multistage gear mechanism, an output shaft and at least two housing halves, the gear mechanism being a spur gear and at least one self-locking A gearing is achieved by means of a drive, wherein the self-locking gear does not form the first gear or the last gear of the gear mechanism.

  According to the invention, a drive is provided for adjusting the aerodynamic flaps on the motor vehicle, the drive comprising an electric motor with a multistage gear mechanism, in particular a spur gear mechanism, so that the multistage gear mechanism comprises a plurality of gear stages And form a self locking stage. This design can maximize efficiency. The self-locking gear does not form the first gear or the last gear of the gear mechanism. By attaching self-locking gear stages to the multiple stages of the gear mechanism, an optimum ratio between the required coupling size and the coupling moment variation can be achieved.

  In this way, a safety coupling can be accommodated between the self-locking stage and the final stage of the multi-stage gear mechanism. In this arrangement, the coupling moment to be transmitted is reduced to one last gear ratio. Thus, the coupling requires less installation space and facilitates the output wheel and output shaft. In principle, for safety couplings, in particular if the self-locking gear is the first gear of the drive, it can be placed closer to the motor gear position, thereby further reducing the size of the coupling However, in that case the variation of the coupling moment will be amplified at all downstream conversion ratios, so the coupling moment at the output drive will be inaccurate. Thus, according to the invention, the self-locking gear stages do not form the first or last stages of the spur gear mechanism.

  The refinements of the invention are given in the dependent claims, the description and the accompanying drawings.

  Preferably, the self-locking gear forms the penultimate gear, and particularly preferably also consists of a spur gear.

  A safety coupling is preferably arranged between the self-locking gear and the output shaft, in particular between the self-locking gear and the output wheel rotatably fixed to the output shaft. This type of safety coupling can disconnect the output drive under overload, in order to protect the flaps mounted on the output drive from damage.

  Preferably, at least one gear is provided between the safety coupling and the output shaft, in particular between the safety coupling and the output wheel.

  The drive preferably comprises a double gear, which comprises a large gear and a small gear coaxial to the large gear, and the safety coupling acts between the large and small gears.

  In particular, the safety coupling can consist of two gear wheels, which are connected to one another via a locking profile, located on the sleeve and pressed together by a compression spring. The sleeve can rotate freely on a fixed axis.

  Preferably, the output wheel rotatably fixed to the output shaft comprises a spring-loaded pretensioned wheel, which protects the tooth flanks of the last gear stage against a strong impact to fluctuating loads.

  The rotation angle of the output drive, in particular the output wheel or the output wheel rotatably fixed to the output shaft, can be detected by measurement.

  Particularly preferably, the support point of the output shaft is completely surrounded by only at least one of the housing parts. A similar drive problem is that gear forces (in this case all the strong forces that occur when disconnecting the safety coupling) are introduced into the housing parts to be welded together and the force flow runs through the weld seams It is. There is therefore a risk of rupturing the seam and losing the seal of the drive, or in the worst case the risk of breakage of the drive. Thus, it is preferred that the output shaft be completely surrounded by one of the housing parts so that gear forces do not have to be absorbed in the joint zone of the housing parts.

  Preferably, at least one gear shaft of the gear is pushed into one housing half and at least all radial forces acting on the shaft are supported by this housing part alone.

  The housing half into which the gear shaft is pushed is preferably the same as that supporting the output shaft.

  The invention is described below by way of example with reference to the drawings.

FIG. 3 is a three-dimensional view of the gear mechanism of the drive according to the invention. FIG. 2 b is a cross-sectional view of a section A-A according to FIG. 2 b of the safety coupling of the drive according to the invention. Fig. 2b shows the position of the section plane A-A of Fig. 2a in a safety coupling. FIG. 2 b shows a three-dimensional exploded view of the safety coupling according to FIGS. Fig. 3 shows three-dimensionally the lower housing for the drive according to the invention. FIG. 4 shows in three dimensions the mounting of the components of the drive according to the invention in the lower housing according to FIG. 3; FIG. 4 is a three-dimensional view of the lower housing according to FIG. 3 with the parts and the intermediate housing attached. FIG. 6 b shows the position of the section plane B-B of FIG. 6 b in the drive according to the invention. FIG. 6b is a cross-sectional view of section B-B according to FIG. 6a of the drive according to the invention;

  FIG. 1 shows the gear mechanism of the drive according to the invention.

  The rotor of the drive motor 1 rotates on a fixed shaft. A first toothing is formed on the hub of the rotor and is connected to the toothing of the first gear 14. The first gear 14 is a two-stage gear, and the two-stage gear is driven by the large spur gear of the two-stage gear, and drives the spur gear 15 of the worm gear via the coaxial small spur gear of the two-stage gear. 15 are mounted on the worm screw 16.

  The worm gear 16 that engages with the worm screw 16 and the worm screw 16, that is, the large gear 6 forms a self-locking gear stage S. Instead of a worm gear stage, another self-locking stage may be used, for example an eccentric gear mechanism or the like.

  The large gear 6 and the small gear 7 are connected to one another via a safety coupling K which is shown in detail in FIGS. 2a, 2b and 2c. The small gear 7 meshes with the output wheel 11. When a certain moment at the output wheel 11 is exceeded, the safety coupling K separates and the output wheel 11 and the pinion 7 can rotate freely.

  A contoured metal plate 17 is pressed onto the surface of the output wheel 11. With the rotational movement of the output wheel 11, this plate 17 moves over the coil mounted in the circuit board, thereby changing the inductance of the coil. This change in inductance can be used to determine the rotation angle of the output wheel 11.

  Furthermore, a spring-loaded pretensioning wheel 12 is arranged on the output wheel 11. The use of this type of pretensioning wheel is known per se for purposes such as noise reduction and vibration reduction. The purpose of the pretensioning wheel 12 in this case is to reduce the knocking of the last gear tooth surface. Excessive tooth play and highly variable loads cause strong impacts on the tooth flanks. In the worst case, plastic deformation of the tooth surface may occur and tooth play may be further increased. A self-amplifying mechanism is activated which can quickly cause the gear to break.

  FIG. 2 three-dimensionally shows the safety coupling K between the large gear 6 and the small gear 7 as shown in FIG. 2c and as a section AA in FIG. 2b as shown in FIG. 2a.

  The two gear wheels 6 and 7 have locking profiles 8 which mesh with one another and are pressed against one another by means of a compression spring 10. During production of the coupling, the spring 10 is compressed to the desired dimensions and the sleeve 9 is mounted (riveted) on the side of the pinion 7. In normal operation, torque can be transmitted between the two gear wheels 6 and 7 via the lock 8 and the coupling K is on a pin fixed in the housing, ie on the coupling shaft 22 (FIG. 4) It rotates with the sleeve 9.

  When an excessive moment is applied to the output drive, the gear wheel 6 is prevented from rotating by the worm screw 16. The lock 8 then pushes the gearwheel 6 axially against the spring 10 until the locking profiles 8 no longer engage one another. The small gear 7 and the sleeve 9 can now rotate freely, but the gear 6 remains stationary until the coupling K reengages. The advantage of this design is that the coupling mechanism K does not create additional tooth play. Similar coupling mechanisms often support one coupling side on the keyed shaft, which must be given a corresponding play to ensure mobility.

  FIG. 3 shows a perspective view of the lower housing 3. The ribs 19, 20 are arranged in the lower housing 3 such that the coupling K and the output wheel 11 can be placed and prearranged in the lower housing 3 for later attachment.

  FIG. 4 shows the lower housing 3 and the gear parts during installation. The gear mechanism of the drive is between the two housing parts bolted to one another, namely the lower housing 3 and the intermediate housing 4. A cover 5 is welded onto the lower housing 3 in order to seal the drive. See also FIGS. 5 and 6b.

  The gear parts excluding the shaft of the coupling K and the output shaft 2 are arranged roughly in advance in the lower housing 3 by the ribs 19, 20. The coupling shaft 22 is pushed into the lower housing 3 from the outside. The output shaft 2 is pushed from the outside into the lower housing 3 and through the output wheel 11 and is held axially by the intermediate housing 4 (FIG. 5). In this design, the high bearing forces that occur, for example, when releasing, are supported only by the lower housing 3 without loading the bolt or weld seam.

  The torque is transmitted from the output wheel 11 to the output shaft 2 via a hexagonal contour on the outer periphery of the output shaft 2. The support point 13 with the highest load is then formed entirely exclusively by the lower housing 3 with corresponding advantages in terms of accuracy and strength.

  FIG. 5 shows the drive with the cover removed. The intermediate housing 4 is bolted to the lower housing 3 by bolts 18. All housing parts and the motor 1 are held by the lower housing 3 and the intermediate housing 4. The cover 5 is welded to the lower housing 3 at the outer edge, and merely serves to seal the drive.

  FIG. 6 b shows the entire drive, ie section B-B through the drive, which passes through the axis of the output shaft 2 shown in FIG. 6 a.

  The output shaft 2 is radially mounted in the lower housing 3 at the support point 13. The support points 13 each have a seal 23. The ribs 21 of the intermediate housing 4 project into the grooves of the output shaft 2 and thus prevent the output shaft 2 from moving axially. The cover 5 is welded to the lower housing 3 at the outer edge. An output wheel 11 with a pretensioning wheel 12 passes through the opening of the intermediate housing 4 to the space between the intermediate housing 4 and the cover 5. A circuit board 24 is also disposed between the intermediate housing 4 and the cover 5 to make angle measurements and / or angle calculations. In particular, on the circuit board 24, the rotation angle of the output wheel 11 or the contoured metal plate 17 located on the output wheel 11 can be detected by measurement.

DESCRIPTION OF SYMBOLS 1 electric motor 2 output shaft 3 lower housing 4 middle housing 5 cover 6 large gear 7 small gear 8 locking contour part 9 sleeve 10 compression spring 11 output wheel 12 pretension wheel 13 support point 14 1st gear 15 worm gear spur gear 16 Worm screw 17 Contoured metal plate 18 Bolt 19 Rib for output wheel 20 Rib for safety coupling 21 Rib for intermediate housing 22 Coupling shaft 23 Seal 24 Circuit board S Self locking gear K Safety coupling

Claims (11)

  A drive for adjusting an aerodynamic flap on a vehicle comprising an electric motor (1), a multistage gear mechanism, an output shaft (2), and at least two housing halves (3, 4, 5), said gear The mechanism comprises spur gears (7, 11, 14, 15) and at least one self-locking gear (S), said self-locking gear (S) also being the last gear of said gear mechanism A driving device characterized in that no step is formed.   The drive according to claim 1, characterized in that the self-locking gear (S) forms the second last gear.   Drive according to claim 1, characterized in that a safety coupling (K) is arranged between the self-locking gear (S) and the output shaft (2).   Drive according to claim 3, characterized in that at least one gear is provided between the safety coupling (K) and the output shaft (2).   The drive comprises two-gears (6, 7), the two-gears (6, 7) comprising a large gear (6) and a small gear (7) coaxial with the large gear (6); Drive according to claim 3, characterized in that the safety coupling (K) acts between the large gear (6) and the small gear (7).   Said safety coupling (K) consists of two gears (6, 7), said two gears (6, 7) being connected to one another via a locking contour (8) and on sleeve (9) 4. Drive according to claim 3, characterized in that it is positioned and pressed together by means of a compression spring (10) so that the sleeve (9) can freely rotate on a fixed shaft.   The output wheel (11) rotatably fixed to the output shaft (2) comprises a spring loaded pretensioning wheel (12), said spring loaded pretensioning wheel (12) being the teeth of said last gear 2. A drive arrangement according to claim 1, characterized in that the surface is protected against strong impacts to fluctuating loads.   2) A device according to claim 1, characterized in that the rotational angle of the output drive, in particular the output wheel (11) rotatably fixed on the output shaft (2) or the output shaft (2), is detected by measurement. Drive device.   Drive according to claim 1, characterized in that the support point (13) of the output shaft (2) is completely surrounded by only one (3) of the housing parts.   Characterized in that at least one gear shaft of a gear stage is pushed into one housing half (3), and all radial forces acting on said shaft are supported by only said housing part (3) The drive device according to claim 1. 10. Drive device according to claim 9, characterized in that the housing half (3) into which the gear shaft is pushed is the same as that supporting the output shaft (2).

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